Technical Abstract:
Ethylenediaminetetraacetic acid (EDTA) and ethylenediamine-N, N’-disuccinic acid (EDDS) are chelating agents that can bind minerals that produce water hardness. By sequestering minerals in hard water, chelators reduce water hardness and increase the ability of cleansers to remove dirt and debris during washing. The objective of this study was to determine if these chelators also possessed microbicidal activity towards bacteria associated with poultry processing. Concentrations of 0, 5, 10, and 20 mM EDTA and EDDS were prepared in 1.0 M potassium hydroxide. The pH of the solutions was adjusted to 11.0 with citric acid, and wells in agar media seeded with bacteria were filled with the solutions. Agar plates were incubated for 24-48 h, and zones of inhibition of bacterial growth around the wells were measured. Statistical analyses of differences in the size of zones of inhibition were performed with the GraphPad InStat® version 3.05 for Windows 95. Results indicated that 10 mM EDTA produced significant (P < 0.05) zones of inhibition of Acinetobacter calcoaceticus, Campylobacter jejuni, Enterococcus faecalis, Pseudomonas fluorescens, and Listeria monocytogenes. Significantly larger zones of inhibition of all bacteria were produced by 20 mM of EDTA than by 10 mM. EDDS only inhibited growth of A. calcoaceticus and P. fluorescens, however. Significant (P < 0.05) zones of inhibition of P. fluorescens were produced by 5 mM of EDDS, while significant zones of inhibition of A. calcoaceticus were produced by 10 mM of EDDS. Furthermore, significantly larger zones of both bacteria were produced by 20 mM of EDDS. The addition of EDTA and EDDS to formulations of sanitizers used in poultry processing may improve the ability of sanitizers to wash away microorganisms on broiler carcasses, but findings from this study also indicate that these chelators may also reduce microbial contamination by killing some bacteria found on processed poultry meat.